Security siren



FIG. 1 is a top perspective view of a security siren showing my new design with broken lines being for illustrative purposes and forming no part of the claimed design;

FIG. 2 is a front elevational view;

FIG. 3 is a back elevational view;

FIG. 4 is a top plan view;

FIG. 5 is a bottom plan view; and,

FIG. 6 is a left side elevational view. 

The ornamental design for a security siren, as shown and described. 